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-rw-r--r--rotord/src/mtrand.cpp50
1 files changed, 50 insertions, 0 deletions
diff --git a/rotord/src/mtrand.cpp b/rotord/src/mtrand.cpp
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+++ b/rotord/src/mtrand.cpp
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+// mtrand.cpp, see include file mtrand.h for information
+
+#include "mtrand.h"
+// non-inline function definitions and static member definitions cannot
+// reside in header file because of the risk of multiple declarations
+
+// initialization of static private members
+unsigned long MTRand_int32::state[n] = {0x0UL};
+int MTRand_int32::p = 0;
+bool MTRand_int32::init = false;
+
+void MTRand_int32::gen_state() { // generate new state vector
+ for (int i = 0; i < (n - m); ++i)
+ state[i] = state[i + m] ^ twiddle(state[i], state[i + 1]);
+ for (int i = n - m; i < (n - 1); ++i)
+ state[i] = state[i + m - n] ^ twiddle(state[i], state[i + 1]);
+ state[n - 1] = state[m - 1] ^ twiddle(state[n - 1], state[0]);
+ p = 0; // reset position
+}
+
+void MTRand_int32::seed(unsigned long s) { // init by 32 bit seed
+ state[0] = s & 0xFFFFFFFFUL; // for > 32 bit machines
+ for (int i = 1; i < n; ++i) {
+ state[i] = 1812433253UL * (state[i - 1] ^ (state[i - 1] >> 30)) + i;
+// see Knuth TAOCP Vol2. 3rd Ed. P.106 for multiplier
+// in the previous versions, MSBs of the seed affect only MSBs of the array state
+// 2002/01/09 modified by Makoto Matsumoto
+ state[i] &= 0xFFFFFFFFUL; // for > 32 bit machines
+ }
+ p = n; // force gen_state() to be called for next random number
+}
+
+void MTRand_int32::seed(const unsigned long* array, int size) { // init by array
+ seed(19650218UL);
+ int i = 1, j = 0;
+ for (int k = ((n > size) ? n : size); k; --k) {
+ state[i] = (state[i] ^ ((state[i - 1] ^ (state[i - 1] >> 30)) * 1664525UL))
+ + array[j] + j; // non linear
+ state[i] &= 0xFFFFFFFFUL; // for > 32 bit machines
+ ++j; j %= size;
+ if ((++i) == n) { state[0] = state[n - 1]; i = 1; }
+ }
+ for (int k = n - 1; k; --k) {
+ state[i] = (state[i] ^ ((state[i - 1] ^ (state[i - 1] >> 30)) * 1566083941UL)) - i;
+ state[i] &= 0xFFFFFFFFUL; // for > 32 bit machines
+ if ((++i) == n) { state[0] = state[n - 1]; i = 1; }
+ }
+ state[0] = 0x80000000UL; // MSB is 1; assuring non-zero initial array
+ p = n; // force gen_state() to be called for next random number
+} \ No newline at end of file